1. Field of the Invention
The present invention relates generally to medical devices and, more specifically, to implantable medical devices.
2. Related Art
There are several types of medical devices that are designed to be temporarily or permanently implanted within a patient or recipient (“recipient” herein). Such medical devices perform one or more of a variety of therapeutic functions such as stimulate nerve or other tissue, monitor biological functions or physiological parameters, transfer materials between the exterior and interior of the recipient, perform functions previously performed by organs or other biological systems, to name a few. Typically, such implantable medical devices include several mechanical, electrical, electro-mechanical and/or electronic components (“functional components” herein) located within an implantable housing. Depending on the application and intended function, the implantable device may be implanted directly underneath the skin or deep within a recipient adjacent to or in an organ or bone of the recipient.
The ability of the implantable device to maintain a hermetic enclosure contributes to the success of an implanted medical device. A hermetic enclosure is required to prevent fluids and tissue from damaging the functional components of the implantable device. The hermetic enclosure is also needed to prevent the implant from causing any adverse interaction within the recipient. For example, a breakdown in the hermetic enclosure may result in pain, infection, or interfere with normal biological and physiological processes. Furthermore, a compromised hermetic enclosure may, for example, cause intermittent functioning and/or a complete malfunction of the implantable medical device. These and other adverse effects may require the removal of the device, or may cause a recipient to stop using the implantable device to avoid the above or other adverse effects. Further, the recipient may be subject to physical events which result in force being applied to the implanted device, causing damage to the hermetic enclosure or the functional components contained therein.
In addition, many implantable devices require the housings to have a relatively thin profile so that when implanted, the device has a limited impact on the recipient. However, conventional designs to improve the hereticity and impact resistance of the enclosure often favor a larger device. A larger implant device may create a necessity for a bone excavation to hold the implant in a desired location and orientation in the recipient. On the other hand, conventional implants having a thin profile often sacrifice impact resistance for size.